I'm seeing references to something Ericsson contributes to their network. It would very interesting to see what went wrong and in particular, what caused the change or deployment to be "un-revertable". My money is on a cascade of issues, some of which were latent and only triggered today.

This is, by far, the worst cell outage I've seen in the UK. There is zero connectivity via O2 in e.g. London, data or otherwise.

There was worse on 7/7/2005 in London due to the bombings. Nearly all the providers fell flat due to overload including land lines and mobile phones. Also public transport was hosed. I walked 11 miles home in the end.

FM radio was about the only thing working. Thank you cheap nokia!

I have an iPhone now which is devoid of an FM radio but carry a multiband VHF transceiver with me most of the time now as that can pick up FM and do comms on 2m (I have an amateur radio license as well).

Best practice is to host the status page on completely separate infrastructure. This adds a lot of operational overhead often seen as disproportionately low benefit relative to the ongoing effort to maintain, until rare events like this actually happen.

Because hosting your own status page seems like a fine idea until your service goes down and 1 million people come to figure out what's wrong or even worse, just lose the entire status page along with your infrastructure.